Technological Field
The present invention relates to an image forming apparatus capable of determining a pass/fail for an image on the basis of a read image obtained by reading a printed matter.
Description of the Related Art
In the field of image forming apparatuses such as copying machines, printers, and multifunction peripherals, apparatuses that analyze a read image obtained by reading an image on a sheet to find an image abnormality and adjust the image quality are known. For example, by determining whether the read image coincides with a correct image such as an image for printing through comparison between the read image and the correct image, it is determined whether image stain, color shift, positional deviation, or the like has occurred, or streak information and the like are found by a failure diagnosis function to diagnose a failed part of the machine. There is also known an apparatus that prints an adjustment image on an insertion sheet, a cutting margin, or the like of the sheet to read and analyzes the adjustment image to adjust the image quality. Also in a case where the image quality is adjusted by reading the adjustment image, an abnormality can be determined according to impossibility of adjustment or the like. When the image is determined to be abnormal, the concerned sheet is regarded to be defective and a process such as discharging a waste sheet to a discharge destination different from that of a regular sheet is performed.
For example, JP 2016-146514 A discloses an apparatus that inspects the quality of a printed matter by reading a sheet for which printing has been completed and comparing a correct image with a scanned image obtained by scanning the printed sheet. In JP 2016-146514 A, a sheet printed in advance is scanned and a scanned image visually checked and ascertained by a user that there is no abnormality therein is used as a correct image.
However, in JP 2016-146514 A, since visual confirmation by the user is necessary when the correct image is created, the work is troublesome and, if the user misses an abnormality, a problem arises that an image having an abnormality is mixed in the correct image.